PHOTOELECTRON SPECTROSCOPIC STUDY OF X-RAY-INDUCED REDUCTION OF CEO2

XPS technique is used to study the modification induced in CeO2 on exp osure to Al K-alpha X-rays. A study of Ce (3d) and O (Is) spectra of s intered and unsintered pellets of ceria with X-ray exposure time is ca rried out to investigate the effect of hydroxyl species on X-ray induc ed reduction of CeO2. After prolonged exposure to X-rays, a colour cha nge is observed on the sample surface of the unsintered pellet. Result s show that the reduction of ceria to sub-stoichiometric oxides occurs at a faster rate in the unsintered pellet on X-ray irradiation. (C) 1 997 Elsevier Science B.V.